The present invention relates to a method for doping semiconductor material employing particle radiation.
In the manufacture of semiconductor elements, e.g. transistors, it is necessary to dope only a thin layer of a semiconductor material, e.g. for the production of pn-junctions and/or connecting contacts. Such doping can be effected by means of low energy ion implantation into a growing molecular beam epitaxy (MBE) layer. For this purpose, the semiconductor material to be doped is exposed to particle radiation (corpuscular radiation) which contains the doping substance in an ionized state, e.g. ionized atoms and/or molecules. During passage through an electrical field, these ions receive high kinetic energy, e.g. approximately 500 eV, so that penetration of the ionized doping substance into the semiconductor material bombarded with it becomes possible.
Such a method has the drawback that it is uneconomical because it requires particularly cost ineffective devices to produce a certain doping profile in a repeatable manner.